main(r,i,j){unsigned long long c;for(;~scanf("%d%d%d",&r,&r,&r)&&r;printf("%llu\n",c*4))for(c=j=0,i=r-1;j!=r;j++)if(i*i+j*j<r*r)c+=i+1;else{while(i*i+j*j>=r*r)i--;c+=i+1;}}
